Can a solicitor be found to have imparted confidential information to a client for another solicitor?

In MacDonald Estate v. Martin, 1990 CanLII 32 (SCC), [1990] 3 S.C.R. 1235, Sopinka J., at p. 1260, addressed the dilemma with which the court is confronted when asked to determine whether confidential information attributable to a solicitor and client relationship was received by a solicitor for another party, where exploring the matter in depth may require the very confidential information for which protection is sought to be revealed, which would defeat the purpose of the application. Sopinka J. held that once it is shown by the client that there existed a previous relationship which is sufficiently related to the retainer from which it is sought to remove the solicitor, the court should infer that confidential information was imparted unless the solicitor satisfies the court that no information was imparted which could be relevant. Sopinka J. observed that this will be a difficult burden to discharge.